Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
01 -1-
PROCESS_FOR UPGRADING HYDROCARBONACEOUS FEEDSTOCKS
05 BACKGRO~ND OF THE INVENTION
_
FIELD OF THE INVENTION
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The present invention relates to a process for
upgrading a hydrocarbonaceous feedstock using a particular
alumina-based catalyst. In a preferred embodiment, the
invention relates to a process for removing metals con-
taminants and sulphur from a heavy hydrocarbonaceous feed,
such as crude petroleum or petroleum residuum.
It is well known that various metallic elements
are found in petroleum crude oils, most commonly, iron,
nickel, and vanadium. These metals are harmful when
included in feedstocks used for further refining opera-
tions. For example, in hydrocracking operations the
plating out of iron metals on the catalyst exterior
surfaces can over a time cause interstitial plugging of
~0 the catalyst bed. Further, deposition of nickel and
vanadium on the interior of catalyst causes catalyst
deactiviation. Thus, efficient removal of contaminants,
particularly metals contaminants, from a hydrocarbonaceous
feedstock is a desired goal~
~5 DESCRIPTION OF THE PRIOR ART
Heretofore, many types of c~talyst have been
proposed for upgrading hydrocarbonaceous feedstocks.
Generally, such catalysts have had high surface areas and
relatively small pore diameters or very low surface areas
combined with high percentages of macropores.
For example, U.S. Patent No. 4,227,995 discloses
a process in which a metal containing hydrocarbon feed-
s~ock is contacted with hydrogen and a material character-
ized by low porosity, low surface area, less than 5 m2/g,
high average pore diameter, greater than 1,000 A, and a
high distribution of large pores, at least 40~ of pores
greater than 10,000 A.
U.S. Patent No. 3,712,861 discloses the
upgrading of hydrocarbons containing sulfur and metal
contaminants with a catalyst containing 0.5-20 wt ~ metal
Ql -2-
sulfides dispersed in an alumina. The catalyst is
characterized with an average pore diameter of about 27~ A
05 and a surface area of about 60-65 m2/g.
U.S. Patent No. 4,0~9,774 relates to a process
for removing metal and sulfur contaminants from residual
oil fractions by contact with a catalyst comprising the
sulfide of a Group VIB metal and iron group metal
supported on an alumina that contains dispersed Delta
and/or Theta phase alumina, the catalyst having at least
45% of its pore volume in pores 30 to 150 A in diameter,
at least 10% of its pore volume in pores least than 30 A
in diameter, and at least 15~ of its pore volume in pores
greater than 300 A in diameter.
Finally, U.S. Patent No. 3,9~7,347 discloses a
process for removing metalliferous contaminants from a
hydrocarbon feedstock by contacting the feedstock in the
presence of hydrogen with an inert particula-te solid
~o having an average pore size in the range of from 1,000 to
10,000 A and a surface area in the range of from 1 to
20 m2/g.
SUMMARY OF THE INVENTION
The present invention relates to a process for
upgrading a hydrocarbonaceous feedstock by contacting the
feedstock in the presence of hydrogenlunder upgrading
conditions with a catalyst comprising alumina, at least a
portion of which is in the alpha phasel said catalyst
having at least about 25% of its pore volume in pores from
300-1,000 A in diameter, having no more than about 10% of
its pore volume in pores greater than 1,000 A in diameter,
and having a surface area of less than about 100 m2/g.
The alumina-based catalyst may also contain a hydrogena-
tion component selected from the group consisting of
transition metals and combinations thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present process is one for upgrading a
hydrocarbonaceous feedstock. Representative feedstocks
include petroleum crude oils, topped or reduced crude
oils, solvent deasphalted oils, distillates, heavy cycled
01 ~3~
stocks, visbreaker liquid effluent, atmospheric and vacuum
crude towered bottoms, shale oils, coal-derived liquids,
oS tar sand oils, etc. Preferred feedstocks include crude
petroleum and petroleum residuum which contain metal con- -
taminants. Although the description herein is directed
particularly to removing metals and sulphur from a
petroleum feedstock, it is understood that the process of
the invention is not so limited.
The catalyst used in the upgrading process of
the present invention comprises alumina, at least a
portion of which is in the alpha phase. Preferably, at
least 35% and most preferably at least 80~ of the alumina
15 is in the alpha phase. The catalyst is further character-
ized by having at least about 25% of its pore volume in
pores from 300-l,000 A in diameter, very large micropores.
Preferably, at least 40% and most preferably 80% of the
pore volume is in these very large micropores. The cata-
lyst is further characterized by haviny Iess than 10% of
its pore volume in macropores l,000 A or greater.
Finally, the catalyst has a low surface area, less than
about lO0 m2/g, preferably about 20 to about 60 m2/g, and
most preferably about 35 m2/g, with pore volume of about
25 0.3 g/cc.
Although it is not essentia~ to the present
invention, the alumina may be composited with a
hydrogenating component if desired. If a hydrogenating
component is present, it is generally selected from the
30 group consisting of transition metals and combinations
thereof, preferably the Coj Ni, Mo, and V. When the term
"metal" is used herein to describe the catalyst, it is
understood that the metal or metal component may exist in
the final catalyst as the metal, as an inorganic compound
35 thereof, or as a mixture of the metal and an inorganic
compound or compounds thereof. Thus, the metal may exist
as the oxide, chloride, sulfide, or the like.
The hydrocarbonaceous feedstock is contacted
with the catalyst of the present invention under upgrading
; 40 conditions which generally include a temperature from
-- 4
about 400 to 1,000F, a pressure of from about 300 to
3,000 psig, and a LHSV of from about 0.1 to 10. For treating
metal contaminated feedstocks, upgrading or demetallizing
conditions include a temperature of from about 600 to 900F,
preferably from about 700 to 800F, a pressure of from about
1,000 -to 3,000 psi~, preferably from about 1,500 to 2,800 psig,
and a LHSV of from about 0.2 to 5.0, preferably from about .2
to 2Ø
The catalyst of the present invention may be used in
many process and/or reactor configurations. For example, the
ca~alyst may be slurried with the feed material. It may be
used as a packed bed in a separate reaction zone or be used in
the first part of a hydro-processing reactor to act as a guard
bed. In a preferred embodiment, the catalyst is part of a
moving bed system and, more preferably, in a two-stage process
in which the effluent from the upgrading or demetallizing zone
is passed upwardly through a fixed bed of hydrocracking
catalyst.
EXAMPLES
The following examples are included to illustrate the
present invention and are not intended to be a limitation
thereon.
Example 1
An alumina catalyst in accordance with the present
invention was prepared from a spherical alumina base having the
following characteristics: 1/16" in diameter, 80% alpha
alumina, 10% Theta alumina and 10% Kappa alumina, a particle
density of 1.283 g/cc, a BET surface area of 36 m2/g, and a
pore size distribution similar to the resultling catalyst.
2.45 g of CoC03 was added to 11.3 ml of phosphomolyb-
dic acid at 100-110F. The solution was cooled to 80F and
then diluted to 160 ml total with distilled water. 300 g of
the above base material was impregnated by the spray pore fill
method and allowed to
ni~
01 ~5~
stand for 20-25 hours. The material was dried at 250F
for 1 hour and then calcined for 18 hours to 950F.
05 The catalyst thus prepared (Catalyst A) had a
particle density of 1.283 g/cc, a skeletal density of
3.752 g/cc, a surface araa of 36 m2/g (measured by the BET
method), a pore volume of 0.513 ml/g, and was 80~ alpha
alumina, 10~ Theta alumina, and 10~ of Kappa alumina.
Catalyst A also contained 0.4~ Co and 1.2~ Mo by weight.
Catalyst B was prepared by a similar method to
Catalyst A but using a different alumina base. Catalyst B
had a skeletal density of 3.512 g/cc, a particle density
of 1.262 g~cc, a BET surface area of 60 m2/g, a pore
vol~lme of 0.508 ml/g, and was 35~ alpha alumina, 50% Theta
alumina and 15~ Kappa alumina. Catalyst B also contained
1.0% Co and 3.0% Mo by weight.
Table I shows the pore distribution of
Catalysts A and B as measured by mercury porosimetry.
;~ ()
Table I
Pore Diameter in A _ % of Pore Volume
Catalyst A CatalYst B
25< 200 6.9 2S.6
200-300 13.1 48.2
300-400 14.1 ~ 15.6
400-600 18.8 8.2
600-800 25.9 1.8
800-1000 14.1 0~6
< 1000 7.1 2.0
Example 2
A Maya atmospheric residuum feed having the
specifications listed in Table II was contacted in
separate runs with each of Catalysts A and B in a tubular
flow reactor at a temperature of 760F, a total pressure
of 2,000 psig, a hydrogen partial pressure of about
1,800 psig, and an LHSV of 0.75. The product inspections
are also shown in Table II. Product A and Product B are
the products from using Catalyst A and Catalyst B,
respectively.
01 -6-
Table II
Sulphur Vanadium Nickel
in wt ~ in ppm in ppm
Feed 4.5 390 61
Product A 2.9 120 42
Product B 2.9 121 39
From the results obtained with Catalyst A, it
can be seen that by employing a catalyst in accordance
with the present invention, it is possible to achieve more
than 0.65 g/cc of reactor of Ni + V demetallation. It was
heretofore generally believed to be impossible to achieve
this or a better result with any other catalyst without
appreciable deactiviation.
Catalyst A was run for about 3,350 hours under
the conditions shown in Example 2 and ]ost only about 20%
of its initial activity for demetallation.
Although one specific embodiment of the present
invention has been described above, it should be under-
stood that this embodiment is described for illustrative
purposes only and that numerous alterations and modifica-
tions can be practiced by those skilled in the art without
the parting from the scope of the invention. Accordingly,
it is the intent that the present invlntion not be limitedby the above, but be limited only as defined in the
appended claims.
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